Factors and multiples MightyOwl Math 4 th Grade

hello this is mighty owl we already know that the product is the answer to multiplication problem but what about the numbers that are being multiplied when two numbers are multiplied together to get product they are called factors factors can be helpful when we are working with multiplication and division for example we know that two multiplied by three is six and this means that two and three are factors of six well can you think of any other numbers that multiply to get six can one and six are also factors of six factors can be positive or negative whole numbers but we're going to focus just on the positive factors what do you say we look at more numbers and their factors what about the number three what numbers multiply to get 3 well 1 and 3 are the only factors when numbers only factors are 1 and itself it's called prime number the number five is another prime number because the only way to get product of five is to multiply one and five and if number has more factors than one and itself then it's called composite number 10 is composite number because you can multiply 1 and 10 or 2 and 5 to get to product of 10. so how can we find the factors of number well great way is to create an organized list we always start with one since all numbers have one as factor and then we work our way up to the number itself so let's try this out let's find all the factors of twenty okay we're going to start with one one multiplied by twenty is equal to that's right twenty next we move on to two two multiplied by ten is equal to twenty next three there's nothing that we can multiply by three to get to twenty when we skip count by threes it goes from 18 to 21 and so 3 isn't factor of 20. moving on to 4 4 multiplied by 5 that's equal to 20 and after 4 comes five ew wait look we already found that five is factor in this means we found all the factors of twenty great job so far we've seen couple of numbers that have two as factor both six and twenty have factors of two and this is because six and twenty are multiples of two multiple is result of multiplying two numbers or count by when you skip count you are listing all of the multiples of the number you are skipping by 2 4 6 8 10 these are all multiples of 2. bet you can keep it going let's try this problem and find the first five multiples of four all right we can do this let's skip count by four okay four 16 20. excellent you just found the first five multiples of four think we can do the next one all right so we need to find all of the factors of 26. okay we can do this let's start with one one multiplied by 26 is 26. good next we can check two yeah two multiplied by thirteen is also twenty six now we can move on to three no three is not factor because 3 times 8 is 24 and 3 times 9 is 27. okay let's try 4 no not 4 because 4 times 6 is 24 and 4 times 7 is 28 okay wow as we continue to go through the numbers after 2 there are no other factors until we get all the way up to 13. okay so the factors of 26 are 1 and 26 all right let's find the factors of 11 remember start with one one multiplied by eleven is eleven okay now let's try two nope not factor since 11 is not an even number okay 3 12 no not three move up onto four moving on to four no five no six it looks like eleven only has the factors of one and eleven that means it's prime number and the factors of eleven are only one and eleven whoa look at all those numbers which of the following numbers are factors of 36 okay the only way to get this done is to organize them to check if they are factors by making two lists factors and not factors okay let's get started we know that 1 is factor so let's move on to 2 multiplied by 18 is 36 yes real quick don't forget about how multiplication and division are related you can also think 36 divided by 2 is what number to find 18. all right so now we have that both 2 and 18 are factors okay next is 3. three multiplied by what is 36 12. okay we found two more factors we're gonna get good at this next is four four multiplied by nine is 36. okay that's two more factors that have been found next we can check six six times six is thirty-six another factor found looks like we're starting to loop back up so we have found all the factors and this means that 5 and 15 are not factors okay the last problem we need to find the multiples of five well that should be too tough we can just skip count by five so let's circle the numbers that are multiples of five okay so we are starting with five so let's circle five now 5 15 20 there you go looks like we found all of the multiples of five great work today you learned about factors and multiples two numbers that are multiplied together are factors and multiples are the count by's and we can skip count to list multiples wow you are expanding your math vocabulary with every lesson how awesome is that